This is a competing renewal application for an institutional NRSA to support the training of four MD and/or PhD postdoctoral fellows. Over the past ten years, this NIH-sponsored award will have provided support for twenty fellows to train in a diverse yet integrated group of laboratories focused in the area of epithelial pathobiology. We have accomplished the goal of training postdoctoral fellows for successful careers in academia. Eleven of the trainees who have been supported by this NRSA have gone on to careers in basic science, clinical medicine, and university teaching. One is a science curriculum evaluator, one is a researcher for the Army, and one is a member of the Centers for Disease Control's Commissioned Corps. Two are pursuing advanced research training. The main goal of this program is to provide multidisciplinary training in problem-oriented research on the pathophysiology of mucosal disease of the alimentary tract with special emphasis on epithelial biology, including epithelial cell function, inflammation, pathogen interactions and neoplasia. The training faculty consists of nineteen investigators with independent research programs related to these areas of study who provide expertise in modern molecular, immunologic, and cell biologic approaches for studying the pathophysiology of disease. There exists particular emphasis on epithelial biology and immunology as it relates to disorders of the gastrointestinal tract. The structure of the training program is designed to continue to promote interactions among participating faculty and to provide trainees access to all of the laboratories and their considerable resources. Trainees will continue to be selected from clinical and graduate programs nationwide with emphasis on identifying qualified underrepresented minorities. The major component of the training program is independent research carried out by trainees in a laboratory of their choice. The training experience is enhanced by attendance at numerous available research conferences, journal clubs, and seminars, as well as attendance at courses provided by the graduate program at Emory, many of which are taught by the faculty of this training program.